"'SOA' doesn't really exist, does it?" Clemens Vasters, co-founder and chief technology officer of newtelligence AG, asks this simple but provocative question in a recent post on his blogsite.
Clemens suggests that many aspects of SOA may be retreads of previous attempts at enterprise integration. "The term “Service Oriented Architecture” implies that there is something special about architecture when it comes to service orientation, Web services, XML, loose coupling and all the wonderful blessings of the past five years," he argues. "But if you look at it, there really isn’t much special about the good, old, proven architectural principles once you throw services into the picture."
He goes on to say that what many people think of as SOA may actually be the "marketing-glorified repackaging of Ethernet, TCP/IP, and LDAP (Enterprise Service Bus), or architectural blueprints that looks strikingly similar to things that people have been doing for a long time with DCE, CORBA, J2EE, COM, or mainframe technologies. What’s different now is that it is easier, cheaper and likely more productive to create bridges between systems. And even that comes at a significant price at this point. Realistically, the Web services stacks yet have to catch up with these 'proprietary' stacks in terms of reliability, security, and performance. "
Clemens' main argument with SOA is that it really doesn't pertain to "architecture" yet. "Service orientation only speaks about the edge -- loose coupling, independent evolution, versioning of contracts, and technology-agnostic metadata exchange," he says. But getting to changes in architecture delves deeper into business processes, and the linkage hasn't been firmly made yet.